-LRB- CNN -RRB- Jeffrey Williams admitted he fired the shots that struck two officers in Ferguson , police said , but claimed he was n't aiming for them .

Nonetheless , the 20-year-old from the St. Louis area has been arrested for the shootings of two police officers during last week 's protests in Ferguson , Missouri , a prosecutor said Sunday .

Williams has been charged with two counts of first-degree assault , a count of firing a weapon from a vehicle and three counts of armed criminal activity , St. Louis County Prosecuting Attorney Bob McCulloch said .

He described Williams as a frequent protester in the city -- which some took issue with .

Bishop Derrick Robinson , an area organizer , said he spoke to Williams on Sunday .

`` I asked him why would he say that he was a protester because it makes us look bad -- because so many things that we 've done to rebuild our community , '' Robinson said . `` It sets us like five steps back to say that it was a protester who did it , but he admitted to me that he 'd never protested . ''

For more than 200 days , protests have taken place in Ferguson since the August shooting death of unarmed black teenager Michael Brown . Ferguson police Officer Darren Wilson was not indicted .

At the time of his arrest , Williams was on probation for receiving stolen property .

The prosecutor thanked the public for the information that led to the arrest . He said police served a search warrant on Williams ' residence where they seized a .40 - caliber handgun , `` which has been tied to the shell casings that were recovered '' at the scene of the shooting .

Williams is being held on a cash-only $ 300,000 bond , McCulloch said , adding that it 's possible Williams could face more charges and that others could be charged in the case .

One element of the case that authorities have yet to sort out is intent , McCulloch said , adding that Williams has acknowledged firing the shots but has said he was n't aiming at the police officers .

Investigators are not sure they `` buy '' Williams ' claim that he opened fire after a dispute with other individuals , McCulloch said , but he did n't rule it out .

`` It 's possible he was firing at someone else , '' he said , urging any other witnesses with information to come forward .

The shots rang out from a hill overlooking the city 's police station shortly after midnight Wednesday , at the end of a protest against the Ferguson Police Department , St. Louis County Police Chief Jon Belmar said at the time .

Officers saw `` muzzle flashes ... about 125 yards away , '' Belmar said .

`` We could have buried two police officers , '' Belmar told reporters last week . `` I feel very confident that whoever did this ... came there for whatever nefarious reason that it was . ''

Public donations poured in to be used toward a reward to find the gunman and any accomplices , Belmar said .

Authorities offered a $ 10,000 reward for information leading to the arrest of person or persons responsible for the gunfire upon the two officers , according to the St. Louis Regional CrimeStoppers website .

McCulloch said the tipster whose information led to Williams ' arrest is eligible to receive the reward .

Protesters said they had nothing to do with the shooting , and that the shots came from a grassy hill away from the crowd .

`` In no way are they representative of the thousands of people ... who have been protesting , '' said Antonio French , a St. Louis alderman .

Belmar believes someone targeted the police , who have faced heated criticism for months , he said .

`` These police officers were standing there , and they were shot just because they were police officers , '' he said .

The department has been criticized since the shooting death of Brown and , more recently , since a scathing U.S. Department of Justice report documented a pattern of racial discrimination in the city . Police Chief Thomas Jackson resigned Wednesday .

`` We are actively addressing the issues that have raised concerns of fairness and fair treatment . We support peaceful protesting . However , we will not allow , nor tolerate , the destructive and violent actions of a few to disrupt our unifying efforts , '' the mayor of Ferguson and the City Council said in a statement Sunday .

While many protesters have decried the Ferguson Police Department , neither of the officers shot last week were from the city .

One is from Webster Groves , a St. Louis suburb 13 miles south of Ferguson . The officer -- a 32-year-old with seven years ' experience -- was shot at the high point of his cheek , just under his right eye , Belmar said .

The other was hit in the shoulder and the bullet came out the middle of his back , Belmar said . He is a 41-year-old officer with the St. Louis County Police Department , who has been in law enforcement for 14 years .

Both men have been treated and released .

CNN 's Carma Hassan , Sara Sidner , Jason Carroll , Shimon Prokupecz , Evan Perez and Alina Machado contributed to this report .

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Jeffrey Williams , 20 , is charged with two counts of first-degree assault , prosecutor says

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Prosecutor thanks the public for leading police to a .40 - caliber allegedly used in shooting

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Two officers , neither from the Ferguson Police Department , were shot during protests last week